There have been a couple of times in the past where I have worked on what I would call "Classic" handle leaks in the Enterprise Vault Outlook Addin. The first issue, fixed a long time ago, related to the recursive function for scanning down folder structures when looking for PSTs to migrate on the client side. This wasn’t correctly unwinding and releasing objects, leading to the leak of 1 handle per folder touched. This became apparent because one particular end-user had >60,000 folders under their "My Documents" structure.

More recently (in fact, it’s still on going at the moment) is an issue with the initial synchronisation of Virtual Vault when there are many folders in the archive. It’s apparent when you get to about 8000 ish folders, and depends somewhat on the Operating System. The result is that you see the following in the client log :

This issue exists in the Enterprise Vault Outlook Addin 9.0.1 and 9.0.2, and possibly other versions. However, it is known to be fixed in the 9.0.2 Cumulative Client Hotfix. See below for a link to that.

When performing the initial synch all of the folders are added to an off-tree area of the MDC file, and then "flipped" over to the visible side. It is this flipping that was leaking. It’s not a 100% classic issue, because I didn’t figure out where in our code this was happening, or whether it was the underlying operations on the PST provider.. but what I did see was the following :

The part on the right was when the initial folder creation was happening, the bit on the left is wrapped around from the right, and shows this "flipping over" happening.